Standard form

What this chapter teaches

Standard form writes a number as A × 10ⁿ, with A from 1 up to, but not including, 10. The digits keep their order. The decimal point slides, and the number of places is the power of ten, positive for big numbers and negative for small ones.

Three questions to ask

There is no one right wording. Listen for the idea.

1. Why is 34 × 10⁷ not standard form, even though it equals 340 000 000?
2. Which way does the point slide for 0.0005, and why is the power negative?
3. How do you decide which of two numbers in standard form is bigger?

After the chapter, the learner can

• Write 340 000 000 as 3.4 × 10⁸
• Write 0.0005 as 5 × 10⁻⁴
• Order numbers written in standard form